ILLINOIS — A developing El Niño pattern in the Pacific Ocean could increase the chances for a snowier winter across parts of Illinois during the 2026-27 season, according to the National Oceanic and Atmospheric Administration’s Climate Prediction Center.
In its latest ENSO Diagnostic Discussion released Thursday, NOAA said El Niño conditions are likely to develop soon and are expected to continue through the Northern Hemisphere winter.
Forecasters said there is an 82% chance El Niño will emerge between May and July 2026 and a 96% chance it will persist through the winter months of December 2026 through February 2027.
El Niño is a climate pattern caused by warmer-than-average water temperatures in the equatorial Pacific Ocean. The pattern can influence weather across the United States, including winter storm tracks and precipitation patterns in the Midwest.
While NOAA emphasized there is still uncertainty regarding how strong this El Niño event may become, stronger El Niño winters have historically increased the likelihood of wetter and stormier conditions across portions of the Midwest. For Illinois, that can sometimes translate into more frequent winter storms and higher snowfall totals, particularly in northern and central parts of the state.
The Climate Prediction Center noted that warmer-than-average subsurface ocean temperatures have continued to strengthen in the Pacific Ocean over the past several months, signaling that El Niño development is becoming more likely.
Meteorologists cautioned that El Niño alone does not guarantee a snowy winter, as temperatures and storm tracks closer to the season will ultimately determine snowfall amounts. However, the developing pattern is already being closely monitored as an early indicator for the upcoming 2026-27 winter season.
